How to install java and set environment variables in linux

What is JAVA?

Java is a programming language designed for use in the distributed environment of the Internet. Java can be used to create complete applications that may run on a single computer or be distributed among servers and clients in a network. It can also be used to build a small application module or applet for use as part of a Web page. Applets make it possible for a Web page user to interact with the page.

Both jdk x64 and x86 installation are same

Step1: Go to oracle website and download Linux jdk (eg: jdk-7u79-linux-i586.gz)

Step2: Extract it to /opt/app/ (or any where you want to be install)

Command: tar -xvf jdk-7u79-linux-i586.gz

After you extract you will see: "jdk1.7.0_79"

/opt/app/jdk1.7.0_79

Create a softlink:

Command: ln -s jdk1.7.0_79 jdk

After you create a softlink you will see: "jdk -> jdk1.7.0_79"

/opt/app/jdk -> jdk1.7.0_79

Step3: Setting environment path globally

create a file jdk.sh with below commands:

Command: vi /etc/profile.d/jdk.sh

Add the below lines and save the file:

export JAVA_HOME=/opt/app/jdk
export PATH=$JAVA_HOME/bin:$PATH

Now source the jdk.sh to use the new jdk

Command: source /etc/profile.d/jdk.sh

confirm jdk installed and environment setup properly:

Command: which java

/opt/app/jdk/bin/java

Command: java -version

java version  "1.7.0_79"

Command: javac -version

javac 1.7.0_79

Note: Softlink helps to avoide making changes to jdk.sh while upgrading jdk to higher version jdk-xxx-linux-i586.gz.

Video Tutorial On How to Install java on Linux